Is now a good time to go big on Passivhaus?

As one of the UK’s largest housing associations unveils plans for a 200-home Passivhaus development in London, is it time others stepped up their sustainable housing offer? 

In April this year, one of the UK’s largest housing associations revealed plans for a brand-new Passivhaus development in south-east London. 

The £75 million, 189-home Deptford Landings development represents one of the largest single-phase Passivhaus schemes delivered in the UK, as well as the first time Peabody has ventured into the realm of Passivhaus. 

Peabody hopes the low-carbon development – which will comprise 100 per cent affordable homes – will significantly reduce energy bills for occupants, helping to reduce fuel poverty, while bolstering the association’s commitment to net zero. 

The provider’s bold foray into Passivhaus comes as the need to deliver on energy efficiency and environmental sustainability grows ever more pressing. And while Peabody is by no means the first housing association to build Passivhaus housing, it is one of the largest.

Should others in the sector be following suit?

The Passivhaus pitch 

Passivhaus (or ‘Passive House’) is an internationally recognised building standard that recognises energy efficiency, reduced carbon footprint and comfortable, healthy, affordable living environments.  

The Passivhaus Institute in Germany first developed the energy-efficient building principles after researching why low-energy buildings frequently were not delivering on their expected energy saving potential. Passivhaus buildings are the gold standard for energy efficiency, maintaining an almost constant temperature, which means they require almost no additional heating or cooling. 

With millions of families across the UK struggling to pay for heating, and who are suffering from the repercussions of damp and mould, it could be argued that there is no better time to build to the Passivhaus Standard and to increase the availability of highly energy-efficient homes for everyone – especially those in need.

“There has been a huge increase in the number of social housing providers across the UK adopting Passivhaus,” explains Sarah Lewis (pictured, right), research and policy director at the Passivhaus Trust. “Several councils and housing associations are leading by example with exciting and sizeable 100-plus home developments. 

“It is crucial to understand the value and sound business case for building to the Passivhaus standard, which is much more than just energy efficiency and thermal performance.” 

The impact of the Passivhaus standard on residents’ quality of life is a major consideration. As Sarah explains, many studies over the past three decades have shown that Passivhaus delivers homes that genuinely perform as designed, eliminating the ‘performance gap’ of standard construction. 

Heating needs can be reduced by up to 90 per cent, while life-changing savings on energy bills can improve the quality of life for tenants and deliver a reduction in rent arrears and fewer void periods. 

Sarah Lewis  |  Passivhaus Trust

It is crucial to understand the value and sound business case for building to the Passivhaus standard, which is much more than just energy efficiency and thermal performance

With so much focus recently on the current condition of many residents’ homes becoming breeding grounds for damp and mould, and the new legislation coming into force to address these issues, residents’ health is also a key incentive to implement the standard. 

“The lack of draughts, cold spots, mould and condensation [in Passivhaus homes] create comfortable temperatures and clean internal environments in both winter and summer, particularly beneficial for more vulnerable residents,” Sarah says. 

“Continuous fresh air provided by the ventilation system provides excellent indoor air quality...Many Passivhaus residents have reported it has helped alleviate allergies such as hay fever and respiratory problems associated with air pollution and mould.” 

Passive progressives 

Peabody’s new 189-home development, delivered with Higgins Partnerships, is entirely committed to the Passivhaus standard. The association has also invested in three members of its design and technical team and one member of its construction inspection teamworking towards and receiving accreditation from the Passive House Institute (PHI) in Germany via a UK training provider. 

David Stronge (pictured, right), Peabody’s design director, who manages a team of recently qualified Passivhaus consultants and specialists, explains how Passivhaus is changing the landscape of Peabody’s future development vision.

“Deptford Landings will be one of the biggest single-phase Passivhaus projects in the UK, and a first for us at Peabody,” he says. 

“As well as being fully affordable, every one of the 189 homes will be low carbon and low energy, helping to significantly reduce bills for residents while being better for the environment.”

To deliver the development, Peabody has ensured design and construction staff are trained and accredited in Passivhaus. It has also sought to learn from others in the field, such as Hastoe Housing Association and Camden Council, who have previous experience delivering Passivhaus schemes. By taking a thorough approach in its preparation, Peabody has been able to design-manage much of the project in house. 

“We understood the full requirements and costs early on – minimising the ‘risk’ premium sometimes paid for this level of energy performance,” David explains. 

“This was not only more cost effective for us, but ensured more certainty when we were tendering for a project partner who received a very advanced level of design from us."

Peabody now has an in-house team of Passivhaus experts, which David says allows it to better advise on briefs for design consultants and work more closely with partners to deliver energy-efficient homes. 

“Training our site inspection staff in Passivhaus will also ensure we’re up to speed in knowing what to expect during construction,” he adds. 

Deptford Landings is set to be Peabody's first Passivhaus development (Cr: Peabody)

Turbo-charging social housing 

The social housing sector has always sought to collaborate with associated industries aligned with its common vision and purpose. Now, it is more important than ever to get these partnerships right if we are to effectively tackle all the current and future challenges the industry faces. 

There are several substantial advantages to be gained from the sector marrying into the Passivhaus standard – and they can make for a handsome pairing when you look at some of the collaborative benefits. 

One of the most obvious is energy efficiency, as building social housing to Passivhaus standards significantly reduces the carbon footprint and helps shield tenants from high heating costs. Reducing the demand for heating and energy can also help reduce the sizes and costs of plant and equipment (e.g. electricity substations) necessary to serve large developments. 

According to a recent OECD report, the UK currently sits at the bottom of the European energy efficiency ranking. By embedding the Passivhaus standard, there is the potential to repair the damage created by decades of sector neglect, whilst making impactful strides towards net zero. 

Passivhaus can also eradicate fuel poverty in new homes, as building energy-efficient homes to the standard slashes the cost of heating a home, which is currently a significant factor in reduced quality of life for millions of UK families.

This links to the third benefit: improved health and wellbeing. Communities predominantly made up of Passivhaus homes tend to exhibit better health and wellbeing compared with those comprised mostly of standard housing.

The Passivhaus Standard aligns with several of the United Nations' Sustainable Development Goals (Cr: Checy/Shutterstock)

The design strategies of Passivhaus contribute to a more comfortable and healthier indoor environment, which positively impacts residents' health. This can also potentially alleviate some of the associated pressures on the NHS. 

Other benefits include alignment with the United Nations’ Sustainable Development Goals (SDGs), as Passivhaus housing reflects many of 17 listed goals, particularly around developing sustainable cities and communities and providing affordable and clean energy; and supporting the Social Housing (Regulation) Act, which has a large focus on improving tenant satisfaction and the safety and quality of homes. 

Stumbling blocks 

As with most significant directional shifts in traditional methods of housebuilding and design, there are several barriers that may need to be overcome if Passivhaus is to truly succeed in social housing. Cost is a big one, as Passivhaus construction is typically more expensive than for a traditional build. 

While the long-term energy savings are substantial, the initial investment required for high-quality insulation, airtightness, and efficient ventilation systems can act as a barrier, which might give some social housing providers cold feet. 

However, Passivhaus Trust research challenges these assumptions, with estimated uplift costs of between four to eight per cent (though some research has produced higher figures) to build to the Passivhaus standard. These costs will likely come down as experience, expertise and economies of scale develop.

“Simple early-stage design and a focus on good form factor and orientation are all effective ways to keep costs down,” the research reads. 

“The long-term energy savings of building to Passivhaus are substantial, and it is worth noting that taking a ‘business as usual’ non-Passivhaus approach can result in additional costs for social housing providers, such as needing to eradicate mould and remedy overheating as well as potentially requiring future upgrades.” 

Additionally, the 2019 report ‘UK housing: Fit for the future?’ highlighted that the average home would require an additional upfront cost of £5,000 to meet efficient heating demands close to Passivhaus standards. Undertaking subsequent retrofit costs and remedial work could cost up to £26,500 per home. 

The technical expertise required to deliver Passivhaus also needs to be considered. Designers and builders must understand the principles of Passivhaus design, including thermal bridging, airtightness, and heat recovery systems. Lack of expertise in these areas could hinder successful implementation. 

Matthew Scott  |  policy and practice officer, CIH

Peabody are showing that we don’t need to wait for regulations to design and build energy-efficient homes that will provide a stable foundation for residents to thrive

Similarly architects, contractors, and other professionals involved in social housing projects may lack the necessary skills and expertise specific to Passivhaus. 

However, this has been improving exponentially in recent years, with training and education all playing a valuable role in bridging this gap. As with other innovative introductions to the housebuilding environment (such as modular), taking the time to get to know and understand what is needed before rushing ahead is vital. 

Finally, resident behaviour will play a crucial role in capitalising on the performance of their new Passivhaus home. Proper use of ventilation systems, windows, and heating controls is essential; however, educating residents about these aspects and encouraging energy-efficient practices can be challenging if they’re used to another type of home.

A better way of living? 

Despite its challenges, the Passivhaus standard has the potential to offer significant benefits to social housing, including better quality long-term assets with fewer defects, reduced energy consumption, improved health and wellbeing, and lower levels of fuel poverty.

By addressing the potential barriers and implementing clear guidelines, the sector can use the Passivhaus Standard to contribute to a more sustainable and comfortable living environment for the UK’s housing residents, whilst also making significant strides in reversing some of the most fundamental housing challenges.

Matthew Scott (pictured, right), a CIH policy and practice officer who leads on net zero, explains the crucial role Passivhaus will play, both in the social housing sector and beyond, in the coming years.

“Building to Passivhaus is undoubtedly one of the best options for reducing space heating demand, tackling fuel poverty, and curtailing carbon emissions in new homes," he says.

"Detailed work published by the Future Homes Hub last year showed just how much it can bring down energy bills, which is especially important for residents in our sector, who tend to have lower incomes due to the way that social housing is allocated based on need.”

He continues: “Looking forward, one of the first things the next government will need to grapple with is introducing the long-delayed Future Homes Standard.

"But as we’ve seen in the social housing sector before, Peabody are showing with their new development that we don’t need to wait for regulations to design and build energy-efficient homes that will provide a stable foundation for residents to thrive.”

Main image: Solar panels are a common feature of Passivhaus housing (Cr: AHatmaker/Shutterstock)